Portable sand blasting device



May 8, 1962 N. P. GLESENER 3,032,929

PORTABLE SAND BLASTING DEVICE Filed March 1'7, 1961 27 28 2o 2 22 I8 3 624 5 I INVENTOR I NORBERTRGLESENER Anormer States 3,032,929 PORTABLESAND BLASTING DEVICE Norbert P. .Glesener, Bird Island, Minn. Filed Mar.17, 1961, Ser. No. 96,443 2 Claims. (Cl. 51-8) Unite type. This is truein particular regard to the equipment associated with the sand blastingwhich contains and transports the sand from its source, or reservoir, tothe blasting head. Also, present sand blasting mechanisms rely, fortheir operation, upon the use of a very large quantity of sand in orderto produce the net result upon the working surface being cleaned,roughened or otherwise conditioned. With these disadvantages of existingequipment in mind, I have devised a new and novel portable sand blasterwhich I now disclose and accordingly:

An object of this invention is to provide a means for blasting sandparticles with compressed air wherein the design requires a minimum ofsand yet provides a maximum net result upon the working surface.

Another object of this invention is to provide a means for blasting sandparticles which allows portability because of the small overall size andlight weight.-

A further object of this invention is to provide an eflicient and simplemeans for adjusting the rate of sand removal from the sand source.

A still further object is to provide a means for direct-- ing an evenpattern of sand upon the working surface.

A further object is to provide a means for blasting sand as set forthabove which is simple and inexpensive in design and operation.

These and other objects and advantages of my invention will more fullyappear from the following description, made in connection with theaccompanying drawing, wherein like reference characters refer to thesame or similar parts throughout the several views and in which:

FIGURE 1 is a side view of my blasting device having elements notnecessary to a full understanding thereof removed, .and further havingportions of the elements shown in cross section;

FIGURE 2 is an enlarged view of the blasting head with portions thereofin cross section to expose the interior construction;

FIGURE 3 is a cross section of FIGURE 2 taken at line 3-3, portionsthereof being in full line drawing; and

FIGURE 4 is a cross sectional view of FIGURE 1 taken at line 44.

Referring now more particularly to FIGURE 1, I provide a sand containeror jar which has mounted thereon a feeding structure 11 which connectswith the blasting head 12 by way of sand hose 13. Also connected to theblasting head 12 is a compressed-air hose 14 which is fed by aconventional air compressor, not shown.

The jar 16 which I provide may be of the conventional glass type havinga capacity of approximately one gallon. The jar 10 has mounted on thetop a conventional cover 15 which secures to the upper threaded portion16 of the neck 17.

As may be seen from FIGURE 1, I have also provided a cover plate 18which is circular in shape and secured to the cover 15 by means of apair of eye bolt nuts 19. Eye bolt nuts 19 serve the dual purpose ofmaintaining ice the cover plate 18 in place as well as securing eyebolts 20 thereto. Secured to eye bolts 20 is a flexible handle means 21.

The cover plate 18 and cover 15 each have an air opening 22 which allowsthe admittance of atmospheric air into the jar and to the granulatedsolids such as sand 23 for reasons to become apparent subsequently. Thecover plate 18 also serves the purpose of reinforcement to the cover 15,which is usually of the thin flexible type of material.

Also located centrally in the cover 15 and cover plate 18 is an opening24 for receiving the threaded portion 25 of the air tube 26. In order tofirmly attach, as well as vertically position the air tube 26 withrespect to the bottom of the jar, I provide the two air tube nuts 27. Asmay be seen in FIGURE 1, I also provide a resilient washer 28 positionedbetween the upper nut 27 and cover plate 18 for the purpose of providinga tight and positive securement of the feeding structure to the cover15.

As may be seen from the cut-away portion of the lower end 29 of the airtube 26, I provide a second or sand tube 30, the lower end 31 of whichterminates slightly above and adjacent to the lower end 29 of air tube26. The sand tube 30, in operation, receives a vacuum from the blastinghead 12, as will be explained subsequently, which thus creates a suckingaction to the sand 23 which is adjacent the lower end 31. With regard tothe flow characteristics of sand, it is readily understood that the sand23 will not seek its own level within the air tube 26 but rather willmaintain itself at a height in the air tube only slightly higher thanthat of the lower end 29. Because of this feature, the sucking action ofthe sand tube 30 will not draw pure sand but rather a mixture of sandgrains and air. and thus a pre-mixing operation of air and sand isaccomplished. The air is received by way of the chamber 33 whichseparates the air tube 26 from the sand tube 30 and which receives itsair supply from the arrangement of collar side opening 34 in collar 35with respect to the circular side opening 36 in the upper portion of airtube 26 (see FIGURE 4).

It may also be explained at this time that the sucking action of thesand tube will cause a slight amount of atmospheric air to be drawnthrough the air openings 22 and 'down through the quantity of sandcontained in the container 10. This action serves the dual purpose ofincreasing the amount of air which is drawn up into the sand tube 30with the sand 23 as well as creating a means for drawing the sand evenlydown into the jar as it is used. In addition, it induces the sandparticles toward the lower end 29 of air tube 26.

Referring now to FIGURE 1 and more specifically to FIGURE 4, the upperend of the air tube 26 is provided with a circular side opening 36.Threadably engaged on the air tube 26 is a collar 35 which has a collarside opening 34 of substantially the same diameter as the opening 36. Itmay readily be seen by those experienced in this type of meteringdevice, that the amount of air admitted to the chamber area 33 will bedependent upon the alignment of the openings 34 and 36, i.e. the lessalignment, as seen in FIGURE 4, the less the amount of air admitted intochamber 33 as indicated by the arrow 37. Also seen in FIGURE 4 is thesand tube 30, shown centrally positioned within the air tube 26.

Secured to the upper end of the air tube 26 is a coupling element 38 forsecuring the sand tube 30 to the upper end of air tube 26 as well asproviding a means for vertically adjusting the sand tube 30 and lowerend 31 with respect to the lower end 29 of air tube 26. Secured to thesand tube at 39 is a sand tube coupling 40 for connecting to the sandhose 13.

Referring now to the blasting head 12 and FIGURE 2 generally, I providea mixer joint 41 which has tbreadably engaged therein, at one end, theair input referred to generally as 42 (see FIGURE 2) and the sand inputreferred to generally as 43. Threadably secured to the other end of themixer joint 41 are the sand and air output tubes referred to as theoutput co-axial nozzle tubing 44.

The air input mechanisms are comprised generally of an air valve 45,which has the conventional control button 46, and is joined to the mixerjoint 41 by means of an elbow joint 47. As seen in FIGURE 2, the airvalve is supplied with an air nipple 48 to which the air hose coupling49 (see FIGURE 1) secures the compressed-air hose 14.

The sand input mechanism consists simply of a connecting tube 50 whichinterconnects the mixer joint :1 and the sand hose 13 by way of saidhose coupler i and connecting tube coupler 52.

As indicated above, the output of the mixer joint consists of a co-axialnozzle tubing 44. This tubing in turn consists of an inner air tube 53and an outer sand tube 54, which is co-axial with air tube 53. As seenin FIG- URE 2, the air tube 53 connects directly to the elbow joint 47(at end 55) which supplies the compressed air. The other end 56terminates in a special configuration shown more clearly in FIGURE 3,which will be explained shortly. The outer sand tube 54, as seen inFIGURE 2, is threadably engaged at end 57 into the mixer joint 41 andhas a head nut 58 secured thereto which, when unscrewed from the threads59 of the outer sand tube 54, will force against the mixer joint 41thereby more rigidly securing the elements to each other. The other endof the outer sand tube 54 has a nozzle reducen coupling 60 threadablyengaged thereto which has also engaged therein, but at the outer end 61,a blasting nozzle 62.

Referring now to FIGURE 2 and FIGURE 3, the special arrangement of theinner air tube 53 will be explained. Since an important feature of mostsand blasting devices is the uniform and symmetrical pattern of the sandspray, it is necessary that, as in this case, the ends of the inner airtube 53 and outer sand tube 54 be co-axially positioned with respect toeach other. It is also necessary that the blasting nozzle 62 be likewiseco-axially positioned with respect to the outer sand tube 54 and theinner air tube 53 There is no problem, of course, in co-axiallypositioning the blasting nozzle 62 because of the arrangement of theconventional nozzle coupling 69; however, there is a slight problem ofpositioning the inner air tube 53 in the outer sand tube 54 so that aneven mixture of air and sand, drawn from the feeding structure 11, maybe drawn to the nozzle chamber 63. To provide this air-sand arrangementas well as a central position of the inner air tube 53, I provide theadapter 64 which has a maximum diameter at points 65 substantially equalto the inside diameter of the outer sand tube 54, and which has aplurality of longitudinal grooves or flutes 66 formed around thecircumference. Grooves 66 are all formed of substantially the same depthand configuration'so that there is a symmetrical flow of air-sandmixture through all of the passageways 67 defined by the grooves 66 andinner bore surface 68 of the outer sand tube 54. The 'air tubeterminates forwardly of the groove portion of the adapter in adiametrically reduced portion 69.

As seen in FIGURE 2, the very end of the adapter 64 has a bushing 70positioned on the inside which effectively reduces the cross sectionalopening area for the compressed air and, which in turn, creates thedrawing or sucking action (necessary for the operation of this type ofdevice) as the air exits through the blasting nozzle 62. The theory andoperation of the air forces will be readily understood and recognized bythose skilled in the art of fluid dynamics.

In the use and operation of my invention, the feeding structure 11 wouldbe inserted in the container 10 and secured thereto after the containerhad been filled with sand. I find that the type of sand is not criticaland any beach type sand is suitable and adequate. The compressed-airhose would, of course, be connected to an air compressor, as indicatedabove, the compressor, for maximum results of the blasting equipment, tohave approximately sixty pounds pressure.

With a working surface 71 (see FIGURE 1) properly oriented, thecontainer filled with sand, and the air compressor operating, theoperator may begin his sand blasting operation by merely pressing thecontrol button 46 of the air valve 45. This operation admits air throughthe inner air tube 53 and at a very high velocity through the reducedportion 69 of the adapter 64, thus creating a vacuum upon the nozzlechamber 63. This vacuum in chamber 63 is transmitted through thepassageways 6'7 to the mixer joint 41 and ultimately through the sandhose 1? to the feeding structure 11. With a vacuum applied to thefeeding structure 11, a sand and air mixture is thus drawn upwardlythrough the lower end 31 of sand tube 30' and ultimately through theblasting head 12 and upon the working surface 71.

It was explained earlier that the collar 35 may be rotated whereby toalign the collar side opening 34 with the circular air tube opening 36in order to vary the amount of air admitted to the sand and air mixturedrawn to the blasting head =12. During the blasting operation, if theoperator desires to impinge a larger quantity of sand upon the workingsurface, he would merely rotate the collar 35 to close off the air tubeopening, thus allowing less air to be premixed with the sand andconsequently a greater amount of lifting or sucking action will beimparted upon the sand 32. As a consequence, a larger amount of sand isdelivered to the working surface.

Through my novel arrangement for sand blasting, I have provided anefiicient means of conditioning a working surface but, as evident fromthe above, with a much desirable portability feature in addition to theusage of a small quantity of sand which is put to an optimum effectiveusage.

It will, of course, be understood that various changes may be made inthe form, details, arrangements, and proportions of the parts withoutdeparting from the scope of my invention as set forth in the appendedclaims.

What is claimed is: i

1. A portable sandblasting apparatus comprising, a

container adapted for holding sand, a feeding structure mounted to saidcontainer for removing sand therefrom when a vacuum is applied thereto,a blasting head having a compressed air input and a sand input connectedto said feeding structure and further having an output co-axial nozzletubing, said co-axial nozzle tubing having an outer sand tubeterminating in a blasting nozzle of reduced cross section forcommunicating therethrough a sand and air mixture from said sand input,and an inner air tube terminating in an adapter having an axial passageconnected to said compressed air input for communicating therethroughcompressed. air from said compressed air input, said adapter havingportions of its outer peripheral surface positioned closely adjacent theinner peripheral diameter of said outer sand tube, the remainingportions of the outer peripheral surface and said inner peripheraldiameter of said outer sand tube defining passageways in communicationwith said sand input adapted for flow of said sand and air mixture, theforward end of said adapter further terminating adjacent and inalignment with said blasting nozzle and at a substantially reduced sizeopening whereby said inner air tube will remain substantially positionedaxially with respect to said blasting nozzle during blastingoperations.

2. A portable sand blasting apparatus comprising, a container adaptedfor holding sand, a cover for said container having an opening thereinfor controlling the and: AL

amount of atmospheric air admitted into said container, a feedingstructure mounted to said container cover for removing sand therefromwhen a vacuum is applied thereto, said feeding structure having an airtube and sand tube disposed Within said air tube, each of which haveportions thereof within said container, means interengaging said coverand said air tube for vertically adjusting said air tube and said sandtube with respect to the bottom of said container and with respect toeach other, a blasting head, means interconnecting said blasting headand said feeding structure for communication of sand and air mixturetherebetween, said blasting head having controllable valving means forintermittently imparting a vacuum to said feeding structure whereby todraw sand and air mixture to said blasting head, and means for blastingsaid sand and air mixture with compressed air upon a working surface.

References Cited in the file of this patent UNITED STATES PATENTS MorelAug. 8, 1950 2,577,465 Jones et a1 Dec. 4, 1951

